1. Field of the Invention
The present invention is directed to a novel hand held hair dryer. More particularly, the present invention 13 directed to a hand held hair dryer having a safety device attached to its exit nozzle.
2. Discussion of the Prior Art
Hand held hair dryers and heat guns produce a heated air stream by passing the air generated from an electric blower over a heating means such as resistance wire. With the tendency to increase wattage in hair dryers the exit temperatures especially close to the air exit, reach temperatures that will singe or otherwise damage the user's hair and can also cause injury to the user's scalp. To prevent injury to the hair or scalp the user must keep the exit portion of the hair dryer a distance away from the hair. This is difficult as hair is a good insulator and may become singed before the user feels excess heat on the scalp. Judgment of the proper distance to maintain between the air exit and the hair is difficult as the heat increases by the square of the distance between the air exit and the hair.
Another problem which exists in commercial hand held hair dryers is that if in use the exit is partially or fully blocked off, the air flow over the heating element is greatly reduced or completely cut off, causing the heating element to overheat resulting in damage to the heating element. Most heat guns and hair dryers have bimetallic thermal protectors, however, due to the thermal delay in their action, the heating element as well as the housing and other parts within the housing are thermally overstressed before the contacts open to stop the current flow to the heating element, reducing their integrity and life. After opening of the contacts and removal of the blockage of the exit causing the overloading of the heating element, a substantial time must pass until the entire system cools down sufficiently and the thermal protector resets. During this period the hair dryer cannot be operated. Additionally, in the event the thermal protector fails or the hair dryer does not contain such a safety device the unit will be permanently damaged and can cause injury to person and property. Thus, the hair dryers existing in the art have not proven to be entirely satisfactory.
Numerous existing patents disclose hand held hair dryers or portable heat guns. Examples of such patents are U.S. Pat. Nos. 3,284,611 and 3,612,824. Neither of these patents recognizes the problems described above and accordingly do not disclose a hair dryer having a guard member with the optimal configuration for the purposes to which this inventor has directed his efforts.